Trace Modes

BitScope performs data capture according to a selected trace mode.

The trace mode controls how many analog channels to capture and what type of timebase to use. It also applies an optional pre and/or post trigger delay to allow data before and/or after to trigger to be captured.

Five registers are used to program the trace mode:

R8Trace RegisterTrace mode selection.
R11Post Trigger DelayDelay after trigger (low byte).
R12Post Trigger DelayDelay after trigger (high byte).
R13Time-base ExpansionTime-base expansion factor.
R20Pre-Trigger DelayBuffer prefill before trigger.

The most important trace mode register is the Trace Register R8. The low 4 bits of this register are programmed to with a Trace ID to select one of 6 available modes:

TM0Simple Trace ModeSingle ChannelLevel Trigger.
TM1Simple Trace ModeDual Channel (Chop) Enhanced Trigger.
TM2Time-base ExpansionSingle ChannelEnhanced Trigger.
TM3Time-base ExpansionDual Channel (Chop)Enhanced Trigger.
TM4Slow Clock ModeDual Channel (Chop)Enhanced Trigger.
TM8Frequency MeasurementN/AN/A

The values to program to the other trace mode registers depend on the selected mode. Also, the upper 4 bits of the Trace Register R8 are reserved and should always be programmed as zero.